Abstract
The restratification in the surface mixed layer driven by a horizontal density gradient following a storm is examined. For a constant layer depth H and contant buoyancy gradient | b sub(x) | =M super(2) , geostrophic adjustment leads to new stratification with N super(2) =M super(4) /[f] super(2) and Richardson number Ri=1. With the inclusion of time dependence, inertial oscillations result and give Ri=1/2. If the horizontal buoyancy gradient is confined, the minimum Ri for an initial distribution of buoyancy b(x) is given by 1-1/2H| b sub(xx) | sub(max) /f super(2) . The resulting maximum restratification is N super(2) =M super(4) /(f super(2) -1/2H| b sub(x) sub(x) ). This restratification can be significant in coastal oceans and possibly in some frontal areas of the open ocean.